1. Field of the Invention
The present invention relates to a manufacturing apparatus of an absorbent article and a manufacturing method of an absorbent article, the apparatus provided with a rotation drum including an adsorbing part that adsorbs a work, which is a component forming a part of the absorbent article.
2. Description of the Related Art
Conventionally, in a manufacturing process of absorbent articles such as disposable diapers, widely used is a manufacturing apparatus of an absorbent article including a work conveying mechanism In the work conveying mechanism, a band-like body formed of successive works, each of which is a component of an absorbent article, is cut into absorbent sheets. The work is specifically an absorbent sheet that absorbs liquid excreted from a target wearing the article (for example, a human body). In addition, the work conveying mechanism rotates an arrangement direction of the absorbent sheet by 90 degrees (for example, see Japanese Patent Application Publication No. 2005-298193 (pp. 6-7, FIG. 1)).
Such a work conveying mechanism includes a rotation drum and multiple adsorbing pads (adsorbing parts) provided on an outer circumference of the rotation drum. The adsorbing pads adsorb the cut absorbent sheets one by one. Then, by the rotation drum, the adsorbed absorbent sheets are sequentially conveyed to above a web on which continuous components of absorbent articles, for example, a back sheet arranged on the outer surfaces of the absorbent sheets and an outer sheet arranged on the outer surface of the back sheet are placed. Each absorbent sheet conveyed to above the web is arranged in a predetermined position of the web conveyed by a conveyor or the like.
For the sake of manufacturing convenience, the band-like body formed of the successive absorbent sheets is manufactured so that a longitudinal direction of each absorbent sheet would be aligned in a longitudinal direction of the band-like body, i.e., a conveyance direction of the band-like body (Machine Direction (MD)). On the other hand, as for the web, employed is a method of arranging each absorbent sheet so that the longitudinal direction of the absorbent sheet is aligned in a cross direction (CD) approximately perpendicular to the conveyance direction of the web. For this reason, the adsorbing pad is rotated by 90 degrees by rotating mechanism included in the rotation drum while being conveyed to above the web by the rotation drum.
Preferably, in order to control different circumferential velocity in the adsorbing pad when the adsorbing pad receives the absorbent sheet, the adsorbing pad, which is provided on an outer circumference of the rotation drum and thereby rotates, preferably receives the absorbent sheet while maintaining a distance of its adsorbing face from the shaft center of the rotation drum as constant as possible. For this reason, the adsorbing face is formed to have a shape in which at least its outer edge portions are inclined toward a shaft center side of the rotation drum, compared with a central portion of the adsorbing face.
However, the above-mentioned conventional manufacturing apparatus of the absorbent article has the following problems. Specifically, since the adsorbing face of the adsorbing pad is formed into the shape in which its outer edge portions are inclined toward the shaft center side of the rotation drum, problems arise such that wrinkles would appear in the absorbent sheet and the absorbent sheet deviates from the predetermined position on the web. This is because, when the adsorbing pad passes the absorbent sheet to the web with an adhesive applied thereon, the absorbent sheet adsorbed by the central portion of the adsorbing face firmly adheres to the web, while the absorbent sheet adsorbed by each outer edge portion is difficult to adhere firmly to the web.
In addition, even when the adsorbing face of the adsorbing pad is formed to have a planar shape, a thickness of the absorbent sheet is changed in some cases and the central portion of the absorbent sheet is therefore thickened. In this case, since the absorbent sheet adsorbed by each outer edge portion is difficult to adhere firmly to the web, similar to the above-mentioned, problems arise such that wrinkles occur in the absorbent sheet and the absorbent sheet deviates from the predetermined position on the web.